Changes to verbosity in writer and reader options.

API changes: Text.Pandoc.Options:

* Added Verbosity.
* Added writerVerbosity.
* Added readerVerbosity.
* Removed writerVerbose.
* Removed readerTrace.

pandoc CLI:  The `--trace` option sets verbosity to DEBUG;
the `--quiet` option sets it to ERROR, and the `--verbose`
option sets it to INFO.  The default is WARNING.

9 files changed, 41 insertions, 35 deletions

diff --git a/src/Text/Pandoc/Options.hs b/src/Text/Pandoc/Options.hs
index e7dec6492..262a0392d 100644
--- a/src/Text/Pandoc/Options.hs
+++ b/src/Text/Pandoc/Options.hs
@@ -37,6 +37,7 @@ module Text.Pandoc.Options ( module Text.Pandoc.Extensions
                            , HTMLSlideVariant (..)
                            , EPUBVersion (..)
                            , WrapOption (..)
+                           , Verbosity (..)
                            , TopLevelDivision (..)
                            , WriterOptions (..)
                            , TrackChanges (..)
@@ -61,7 +62,7 @@ data ReaderOptions = ReaderOptions{
        , readerIndentedCodeClasses :: [String] -- ^ Default classes for
                                        -- indented code blocks
        , readerDefaultImageExtension :: String -- ^ Default extension for images
-       , readerTrace           :: Bool -- ^ Print debugging info
+       , readerVerbosity       :: Verbosity -- ^ Verbosity level
        , readerTrackChanges    :: TrackChanges
 } deriving (Show, Read, Data, Typeable, Generic)
 
@@ -75,7 +76,7 @@ instance Default ReaderOptions
                , readerApplyMacros           = True
                , readerIndentedCodeClasses   = []
                , readerDefaultImageExtension = ""
-               , readerTrace                 = False
+               , readerVerbosity             = ERROR
                , readerTrackChanges          = AcceptChanges
                }
 
@@ -141,6 +142,10 @@ data ReferenceLocation = EndOfBlock    -- ^ End of block
                        | EndOfDocument -- ^ at end of document
                        deriving (Show, Read, Eq, Data, Typeable, Generic)
 
+-- | Verbosity level.
+data Verbosity = ERROR | WARNING | INFO | DEBUG
+     deriving (Show, Read, Eq, Data, Enum, Ord, Bounded, Typeable, Generic)
+
 -- | Options for writers
 data WriterOptions = WriterOptions
   { writerTemplate         :: Maybe String -- ^ Template to use
@@ -181,7 +186,7 @@ data WriterOptions = WriterOptions
   , writerEpubChapterLevel :: Int            -- ^ Header level for chapters (separate files)
   , writerTOCDepth         :: Int            -- ^ Number of levels to include in TOC
   , writerReferenceDoc     :: Maybe FilePath -- ^ Path to reference document if specified
-  , writerVerbose          :: Bool           -- ^ Verbose debugging output
+  , writerVerbosity        :: Verbosity      -- ^ Verbose debugging output
   , writerLaTeXArgs        :: [String]       -- ^ Flags to pass to latex-engine
   , writerReferenceLocation :: ReferenceLocation    -- ^ Location of footnotes and references for writing markdown
   } deriving (Show, Data, Typeable, Generic)
@@ -223,7 +228,7 @@ instance Default WriterOptions where
                       , writerEpubChapterLevel = 1
                       , writerTOCDepth         = 3
                       , writerReferenceDoc     = Nothing
-                      , writerVerbose          = False
+                      , writerVerbosity        = WARNING
                       , writerLaTeXArgs        = []
                       , writerReferenceLocation = EndOfDocument
                       }
diff --git a/src/Text/Pandoc/PDF.hs b/src/Text/Pandoc/PDF.hs
index be889c052..cc523febf 100644
--- a/src/Text/Pandoc/PDF.hs
+++ b/src/Text/Pandoc/PDF.hs
@@ -52,7 +52,8 @@ import Text.Pandoc.MediaBag
 import Text.Pandoc.Walk (walkM)
 import Text.Pandoc.Shared (warn, withTempDir, inDirectory, stringify)
 import Text.Pandoc.Writers.Shared (getField, metaToJSON)
-import Text.Pandoc.Options (WriterOptions(..), HTMLMathMethod(..))
+import Text.Pandoc.Options (WriterOptions(..), HTMLMathMethod(..),
+          Verbosity(..))
 import Text.Pandoc.MIME (extensionFromMimeType, getMimeType)
 import Text.Pandoc.Process (pipeProcess)
 import Control.Monad.Trans (MonadIO(..))
@@ -98,16 +99,16 @@ makePDF "wkhtmltopdf" writer opts _mediabag doc@(Pandoc meta _) = liftIO $ do
                             (getField "margin-left" meta'))
                  ]
   source <- runIOorExplode $ writer opts doc
-  html2pdf (writerVerbose opts) args source
+  html2pdf (writerVerbosity opts) args source
 makePDF program writer opts mediabag doc =
   liftIO $ withTempDir "tex2pdf." $ \tmpdir -> do
     doc' <- handleImages opts mediabag tmpdir doc
     source <- runIOorExplode $ writer opts doc'
     let args   = writerLaTeXArgs opts
     case takeBaseName program of
-       "context" -> context2pdf (writerVerbose opts) tmpdir source
+       "context" -> context2pdf (writerVerbosity opts) tmpdir source
        prog | prog `elem` ["pdflatex", "lualatex", "xelatex"]
-           -> tex2pdf' (writerVerbose opts) args tmpdir program source
+           -> tex2pdf' (writerVerbosity opts) args tmpdir program source
        _ -> return $ Left $ UTF8.fromStringLazy $ "Unknown program " ++ program
 
 handleImages :: WriterOptions
@@ -174,17 +175,17 @@ convertImage tmpdir fname =
     mime = getMimeType fname
     doNothing = return (Right fname)
 
-tex2pdf' :: Bool                            -- ^ Verbose output
+tex2pdf' :: Verbosity                       -- ^ Verbosity level
          -> [String]                        -- ^ Arguments to the latex-engine
          -> FilePath                        -- ^ temp directory for output
          -> String                          -- ^ tex program
          -> String                          -- ^ tex source
          -> IO (Either ByteString ByteString)
-tex2pdf' verbose args tmpDir program source = do
+tex2pdf' verbosity args tmpDir program source = do
   let numruns = if "\\tableofcontents" `isInfixOf` source
                    then 3  -- to get page numbers
                    else 2  -- 1 run won't give you PDF bookmarks
-  (exit, log', mbPdf) <- runTeXProgram verbose program args 1 numruns tmpDir source
+  (exit, log', mbPdf) <- runTeXProgram verbosity program args 1 numruns tmpDir source
   case (exit, mbPdf) of
        (ExitFailure _, _)      -> do
           let logmsg = extractMsg log'
@@ -222,9 +223,9 @@ extractConTeXtMsg log' = do
 -- Run a TeX program on an input bytestring and return (exit code,
 -- contents of stdout, contents of produced PDF if any).  Rerun
 -- a fixed number of times to resolve references.
-runTeXProgram :: Bool -> String -> [String] -> Int -> Int -> FilePath -> String
-              -> IO (ExitCode, ByteString, Maybe ByteString)
-runTeXProgram verbose program args runNumber numRuns tmpDir source = do
+runTeXProgram :: Verbosity -> String -> [String] -> Int -> Int -> FilePath
+              -> String -> IO (ExitCode, ByteString, Maybe ByteString)
+runTeXProgram verbosity program args runNumber numRuns tmpDir source = do
     let file = tmpDir </> "input.tex"
     exists <- doesFileExist file
     unless exists $ UTF8.writeFile file source
@@ -244,7 +245,7 @@ runTeXProgram verbose program args runNumber numRuns tmpDir source = do
           $ lookup "TEXINPUTS" env'
     let env'' = ("TEXINPUTS", texinputs) :
                   [(k,v) | (k,v) <- env', k /= "TEXINPUTS"]
-    when (verbose && runNumber == 1) $ do
+    when (verbosity >= INFO && runNumber == 1) $ do
       putStrLn "[makePDF] temp dir:"
       putStrLn tmpDir'
       putStrLn "[makePDF] Command line:"
@@ -257,12 +258,12 @@ runTeXProgram verbose program args runNumber numRuns tmpDir source = do
       B.readFile file' >>= B.putStr
       putStr "\n"
     (exit, out) <- pipeProcess (Just env'') program programArgs BL.empty
-    when verbose $ do
+    when (verbosity >= INFO) $ do
       putStrLn $ "[makePDF] Run #" ++ show runNumber
       B.hPutStr stdout out
       putStr "\n"
     if runNumber <= numRuns
-       then runTeXProgram verbose program args (runNumber + 1) numRuns tmpDir source
+       then runTeXProgram verbosity program args (runNumber + 1) numRuns tmpDir source
        else do
          let pdfFile = replaceDirectory (replaceExtension file ".pdf") tmpDir
          pdfExists <- doesFileExist pdfFile
@@ -274,17 +275,17 @@ runTeXProgram verbose program args runNumber numRuns tmpDir source = do
                    else return Nothing
          return (exit, out, pdf)
 
-html2pdf  :: Bool         -- ^ Verbose output
+html2pdf  :: Verbosity    -- ^ Verbosity level
           -> [String]     -- ^ Args to wkhtmltopdf
           -> String       -- ^ HTML5 source
           -> IO (Either ByteString ByteString)
-html2pdf verbose args source = do
+html2pdf verbosity args source = do
   file <- withTempFile "." "html2pdf.html" $ \fp _ -> return fp
   pdfFile <- withTempFile "." "html2pdf.pdf" $ \fp _ -> return fp
   UTF8.writeFile file source
   let programArgs = args ++ [file, pdfFile]
   env' <- getEnvironment
-  when verbose $ do
+  when (verbosity >= INFO) $ do
     putStrLn "[makePDF] Command line:"
     putStrLn $ "wkhtmltopdf" ++ " " ++ unwords (map show programArgs)
     putStr "\n"
@@ -296,7 +297,7 @@ html2pdf verbose args source = do
     putStr "\n"
   (exit, out) <- pipeProcess (Just env') "wkhtmltopdf" programArgs BL.empty
   removeFile file
-  when verbose $ do
+  when (verbosity >= INFO) $ do
     B.hPutStr stdout out
     putStr "\n"
   pdfExists <- doesFileExist pdfFile
@@ -314,11 +315,11 @@ html2pdf verbose args source = do
              (ExitSuccess, Nothing)  -> Left ""
              (ExitSuccess, Just pdf) -> Right pdf
 
-context2pdf :: Bool         -- ^ Verbose output
+context2pdf :: Verbosity    -- ^ Verbosity level
             -> FilePath     -- ^ temp directory for output
             -> String       -- ^ ConTeXt source
             -> IO (Either ByteString ByteString)
-context2pdf verbose tmpDir source = inDirectory tmpDir $ do
+context2pdf verbosity tmpDir source = inDirectory tmpDir $ do
   let file = "input.tex"
   UTF8.writeFile file source
 #ifdef _WINDOWS
@@ -334,7 +335,7 @@ context2pdf verbose tmpDir source = inDirectory tmpDir $ do
         $ lookup "TEXINPUTS" env'
   let env'' = ("TEXINPUTS", texinputs) :
                 [(k,v) | (k,v) <- env', k /= "TEXINPUTS"]
-  when verbose $ do
+  when (verbosity >= INFO) $ do
     putStrLn "[makePDF] temp dir:"
     putStrLn tmpDir'
     putStrLn "[makePDF] Command line:"
@@ -347,7 +348,7 @@ context2pdf verbose tmpDir source = inDirectory tmpDir $ do
     B.readFile file >>= B.putStr
     putStr "\n"
   (exit, out) <- pipeProcess (Just env'') "context" programArgs BL.empty
-  when verbose $ do
+  when (verbosity >= INFO) $ do
     B.hPutStr stdout out
     putStr "\n"
   let pdfFile = replaceExtension file ".pdf"
diff --git a/src/Text/Pandoc/Readers/EPUB.hs b/src/Text/Pandoc/Readers/EPUB.hs
index a76ed04ba..71a527f13 100644
--- a/src/Text/Pandoc/Readers/EPUB.hs
+++ b/src/Text/Pandoc/Readers/EPUB.hs
@@ -12,7 +12,7 @@ import Text.XML.Light
 import Text.Pandoc.Definition hiding (Attr)
 import Text.Pandoc.Readers.HTML (readHtml)
 import Text.Pandoc.Walk (walk, query)
-import Text.Pandoc.Options ( ReaderOptions(..), readerTrace)
+import Text.Pandoc.Options ( ReaderOptions(..), readerVerbosity, Verbosity(..))
 import Text.Pandoc.Shared (escapeURI, collapseFilePath, addMetaField)
 import Network.URI (unEscapeString)
 import Text.Pandoc.MediaBag (MediaBag, insertMedia)
@@ -71,7 +71,7 @@ archiveToEPUB os archive = do
     os' = os {readerParseRaw = True}
     parseSpineElem :: PandocMonad m => FilePath -> (FilePath, MimeType) -> m Pandoc
     parseSpineElem (normalise -> r) (normalise -> path, mime) = do
-      when (readerTrace os) (traceM path)
+      when (readerVerbosity os == DEBUG) (traceM path)
       doc <- mimeToReader mime r path
       let docSpan = B.doc $ B.para $ B.spanWith (takeFileName path, [], []) mempty
       return $ docSpan <> doc
diff --git a/src/Text/Pandoc/Readers/HTML.hs b/src/Text/Pandoc/Readers/HTML.hs
index b66a712e0..d602f7303 100644
--- a/src/Text/Pandoc/Readers/HTML.hs
+++ b/src/Text/Pandoc/Readers/HTML.hs
@@ -45,8 +45,8 @@ import qualified Text.Pandoc.Builder as B
 import Text.Pandoc.Builder (Blocks, Inlines, trimInlines, HasMeta(..))
 import Text.Pandoc.Shared ( extractSpaces, renderTags', addMetaField
                           , escapeURI, safeRead )
-import Text.Pandoc.Options (ReaderOptions(readerParseRaw, readerTrace)
-                           , Extension (Ext_epub_html_exts,
+import Text.Pandoc.Options (ReaderOptions(readerParseRaw, readerVerbosity),
+                            Verbosity(..), Extension (Ext_epub_html_exts,
                                Ext_native_divs, Ext_native_spans))
 import Text.Pandoc.Parsing hiding ((<|>))
 import Text.Pandoc.Walk
@@ -160,7 +160,7 @@ pHead = pInTags "head" $ pTitle <|> pMetaTag <|> pBaseTag <|> (mempty <$ pAnyTag
 
 block :: PandocMonad m => TagParser m Blocks
 block = do
-  tr <- getOption readerTrace
+  tr <- (== DEBUG) <$> getOption readerVerbosity
   pos <- getPosition
   res <- choice
             [ eSection
diff --git a/src/Text/Pandoc/Readers/Haddock.hs b/src/Text/Pandoc/Readers/Haddock.hs
index 987342bf7..575d99c77 100644
--- a/src/Text/Pandoc/Readers/Haddock.hs
+++ b/src/Text/Pandoc/Readers/Haddock.hs
@@ -48,7 +48,7 @@ readHaddockEither opts =
 #else
   Right .  B.doc . docHToBlocks . trace' . parseParas
 #endif
-  where trace' x = if readerTrace opts
+  where trace' x = if readerVerbosity opts == DEBUG
                       then trace (show x) x
                       else x
 
diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 9137ae4b6..e0036f708 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -490,7 +490,7 @@ parseBlocks = mconcat <$> manyTill block eof
 
 block :: PandocMonad m => MarkdownParser m (F Blocks)
 block = do
-  tr <- getOption readerTrace
+  tr <- (== DEBUG) <$> getOption readerVerbosity
   pos <- getPosition
   res <- choice [ mempty <$ blanklines
                , codeBlockFenced
diff --git a/src/Text/Pandoc/Readers/MediaWiki.hs b/src/Text/Pandoc/Readers/MediaWiki.hs
index 5bdf0ca4e..38a9e3f4f 100644
--- a/src/Text/Pandoc/Readers/MediaWiki.hs
+++ b/src/Text/Pandoc/Readers/MediaWiki.hs
@@ -194,7 +194,7 @@ parseMediaWiki = do
 
 block :: PandocMonad m => MWParser m Blocks
 block = do
-  tr <- getOption readerTrace
+  tr <- (== DEBUG) <$> getOption readerVerbosity
   pos <- getPosition
   res <- mempty <$ skipMany1 blankline
      <|> table
diff --git a/src/Text/Pandoc/Readers/TWiki.hs b/src/Text/Pandoc/Readers/TWiki.hs
index 3e547e5f4..b54eec735 100644
--- a/src/Text/Pandoc/Readers/TWiki.hs
+++ b/src/Text/Pandoc/Readers/TWiki.hs
@@ -127,7 +127,7 @@ parseTWiki = do
 
 block :: TWParser B.Blocks
 block = do
-  tr <- getOption readerTrace
+  tr <- (== DEBUG) <$> getOption readerVerbosity
   pos <- getPosition
   res <- mempty <$ skipMany1 blankline
          <|> blockElements
diff --git a/src/Text/Pandoc/Readers/Textile.hs b/src/Text/Pandoc/Readers/Textile.hs
index 404913926..b3a1a208f 100644
--- a/src/Text/Pandoc/Readers/Textile.hs
+++ b/src/Text/Pandoc/Readers/Textile.hs
@@ -147,7 +147,7 @@ block :: PandocMonad m => ParserT [Char] ParserState m Blocks
 block = do
   res <- choice blockParsers <?> "block"
   pos <- getPosition
-  tr <- getOption readerTrace
+  tr <- (== DEBUG) <$> getOption readerVerbosity
   when tr $
     trace (printf "line %d: %s" (sourceLine pos)
            (take 60 $ show $ B.toList res)) (return ())